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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-01-24 14:11:53 +0100 |
|---|---|---|
| committer | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-02-21 16:43:14 +0100 |
| commit | 9ed3f22223c33347ed963e7c7019cf2956dd4e37 (patch) | |
| tree | ed5d8fc6e40538ca8bac3256aebc291d0bef064b /drivers/hwtracing/intel_th | |
| parent | intel_th: pti: Use sysfs_match_string() helper (diff) | |
| download | linux-9ed3f22223c33347ed963e7c7019cf2956dd4e37.tar.xz linux-9ed3f22223c33347ed963e7c7019cf2956dd4e37.zip | |
intel_th: Don't reference unassigned outputs
When an output port driver is removed, also remove references to it from
any masters. Failing to do this causes a NULL ptr dereference when
configuring another output port:
> BUG: unable to handle kernel NULL pointer dereference at 000000000000000d
> RIP: 0010:master_attr_store+0x9d/0x160 [intel_th_gth]
> Call Trace:
> dev_attr_store+0x1b/0x30
> sysfs_kf_write+0x3c/0x50
> kernfs_fop_write+0x125/0x1a0
> __vfs_write+0x3a/0x190
> ? __vfs_write+0x5/0x190
> ? _cond_resched+0x1a/0x50
> ? rcu_all_qs+0x5/0xb0
> ? __vfs_write+0x5/0x190
> vfs_write+0xb8/0x1b0
> ksys_write+0x55/0xc0
> __x64_sys_write+0x1a/0x20
> do_syscall_64+0x5a/0x140
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: b27a6a3f97b9 ("intel_th: Add Global Trace Hub driver")
CC: stable@vger.kernel.org # v4.4+
Reported-by: Ammy Yi <ammy.yi@intel.com>
Diffstat (limited to 'drivers/hwtracing/intel_th')
| -rw-r--r-- | drivers/hwtracing/intel_th/gth.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/hwtracing/intel_th/gth.c b/drivers/hwtracing/intel_th/gth.c index 8426b7970c14..cc287cf6eb29 100644 --- a/drivers/hwtracing/intel_th/gth.c +++ b/drivers/hwtracing/intel_th/gth.c @@ -607,6 +607,7 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev, { struct gth_device *gth = dev_get_drvdata(&thdev->dev); int port = othdev->output.port; + int master; if (thdev->host_mode) return; @@ -615,6 +616,9 @@ static void intel_th_gth_unassign(struct intel_th_device *thdev, othdev->output.port = -1; othdev->output.active = false; gth->output[port].output = NULL; + for (master = 0; master < TH_CONFIGURABLE_MASTERS; master++) + if (gth->master[master] == port) + gth->master[master] = -1; spin_unlock(>h->gth_lock); } |